RESUMEN
The classical model of hematopoiesis established in the mouse postulates that lymphoid cells originate from a founder population of common lymphoid progenitors. Here, using a modeling approach in humanized mice, we showed that human lymphoid development stemmed from distinct populations of CD127- and CD127+ early lymphoid progenitors (ELPs). Combining molecular analyses with in vitro and in vivo functional assays, we demonstrated that CD127- and CD127+ ELPs emerged independently from lympho-mono-dendritic progenitors, responded differently to Notch1 signals, underwent divergent modes of lineage restriction, and displayed both common and specific differentiation potentials. Whereas CD127- ELPs comprised precursors of T cells, marginal zone B cells, and natural killer (NK) and innate lymphoid cells (ILCs), CD127+ ELPs supported production of all NK cell, ILC, and B cell populations but lacked T potential. On the basis of these results, we propose a "two-family" model of human lymphoid development that differs from the prevailing model of hematopoiesis.
Asunto(s)
Linfocitos B/metabolismo , Células Asesinas Naturales/metabolismo , Células Progenitoras Linfoides/metabolismo , Linfopoyesis/genética , Linfocitos T/metabolismo , Adolescente , Adulto , Animales , Linfocitos B/citología , Diferenciación Celular/genética , Linaje de la Célula/genética , Células Cultivadas , Femenino , Perfilación de la Expresión Génica/métodos , Humanos , Subunidad gamma Común de Receptores de Interleucina/deficiencia , Subunidad gamma Común de Receptores de Interleucina/genética , Subunidad alfa del Receptor de Interleucina-7/genética , Subunidad alfa del Receptor de Interleucina-7/metabolismo , Células Asesinas Naturales/citología , Células Progenitoras Linfoides/citología , Células Progenitoras Linfoides/trasplante , Masculino , Ratones Endogámicos NOD , Ratones Noqueados , Ratones SCID , Persona de Mediana Edad , Trasplante de Células Madre , Linfocitos T/citología , Trasplante Heterólogo , Adulto JovenRESUMEN
Natural killer (NK) cells are major antileukemic immune effectors. Leukemic blasts have a negative impact on NK cell function and promote the emergence of phenotypically and functionally impaired NK cells. In the current work, we highlight an accumulation of CD56-CD16+ unconventional NK cells in acute myeloid leukemia (AML), an aberrant subset initially described as being elevated in patients chronically infected with HIV-1. Deep phenotyping of NK cells was performed using peripheral blood from patients with newly diagnosed AML (n = 48, HEMATOBIO cohort, NCT02320656) and healthy subjects (n = 18) by mass cytometry. We showed evidence of a moderate to drastic accumulation of CD56-CD16+ unconventional NK cells in 27% of patients. These NK cells displayed decreased expression of NKG2A as well as the triggering receptors NKp30 and NKp46, in line with previous observations in HIV-infected patients. High-dimensional characterization of these NK cells highlighted a decreased expression of three additional major triggering receptors required for NK cell activation, NKG2D, DNAM-1, and CD96. A high proportion of CD56-CD16+ NK cells at diagnosis was associated with an adverse clinical outcome and decreased overall survival (HR = 0.13; P = 0.0002) and event-free survival (HR = 0.33; P = 0.018) and retained statistical significance in multivariate analysis. Pseudotime analysis of the NK cell compartment highlighted a disruption of the maturation process, with a bifurcation from conventional NK cells toward CD56-CD16+ NK cells. Overall, our data suggest that the accumulation of CD56-CD16+ NK cells may be the consequence of immune escape from innate immunity during AML progression.
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Citometría de Flujo/métodos , Células Asesinas Naturales/inmunología , Leucemia Mieloide Aguda/inmunología , Leucemia Mieloide Aguda/patología , Antígenos CD/inmunología , Humanos , Inmunofenotipificación , Activación de Linfocitos/inmunología , Inducción de Remisión , Resultado del TratamientoRESUMEN
The extrafollicular immune response is essential to generate a rapid but transient wave of protective antibodies during infection. Despite its importance, the molecular mechanisms controlling this first response are poorly understood. Here, we demonstrate that enhanced Cxcr4 signaling caused by defective receptor desensitization leads to exacerbated extrafollicular B-cell response. Using a mouse model bearing a gain-of-function mutation of Cxcr4 described in 2 human hematologic disorders, warts, hypogammaglobulinemia, infections, and myelokathexis (WHIM) syndrome and Waldenström macroglobulinemia, we demonstrated that mutant B cells exhibited enhanced mechanistic target of rapamycin signaling, cycled more, and differentiated more potently into plasma cells than wild-type B cells after Toll-like receptor (TLR) stimulation. Moreover, Cxcr4 gain of function promoted enhanced homing and persistence of immature plasma cells in the bone marrow, a phenomenon recapitulated in WHIM syndrome patient samples. This translated in increased and more sustained production of antibodies after T-independent immunization in Cxcr4 mutant mice. Thus, our results establish that fine-tuning of Cxcr4 signaling is essential to limit the strength and length of the extrafollicular immune response.
Asunto(s)
Mutación con Ganancia de Función , Enfermedades Hematológicas/inmunología , Células Plasmáticas/inmunología , Receptores CXCR4/inmunología , Transducción de Señal/inmunología , Animales , Enfermedades Hematológicas/genética , Humanos , Ratones , Ratones Transgénicos , Receptores CXCR4/genética , Transducción de Señal/genética , Serina-Treonina Quinasas TOR/genética , Serina-Treonina Quinasas TOR/inmunologíaRESUMEN
Human SETD2 is the unique histone methyltransferase that generates H3K36 trimethylation (H3K36me3), an epigenetic mark that plays a key role in normal hematopoiesis. Interestingly, recurrent inactivating mutations of SETD2 and aberrant H3K36me3 are increasingly reported to be involved in hematopoietic malignancies. Benzene (BZ) is a ubiquitous environmental pollutant and carcinogen that causes leukemia. The leukemogenic properties of BZ depend on its biotransformation in the bone marrow into oxidative metabolites, in particular 1,4-benzoquinone (BQ). This hematotoxic metabolite can form DNA and protein adducts that result in the damage and the alteration of cellular processes. Recent studies suggest that BZ-dependent leukemogenesis could depend on epigenetic perturbations, notably aberrant histone methylation. We investigated whether H3K36 trimethylation by SETD2 could be impacted by BZ and its hematotoxic metabolites. Herein, we show that BQ, the major leukemogenic metabolite of BZ, inhibits irreversibly the human histone methyltransferase SETD2, resulting in decreased H3K36me3. Our mechanistic studies further indicate that the BQ-dependent inactivation of SETD2 is due to covalent binding of BQ to reactive Zn-finger cysteines within the catalytic domain of the enzyme. The formation of these quinoprotein adducts results in loss of enzyme activity and protein crosslinks/oligomers. Experiments conducted in hematopoietic cells confirm that exposure to BQ results in the formation of SETD2 crosslinks/oligomers and concomitant loss of H3K36me3 in cells. Taken together, our data indicate that BQ, a major hematotoxic metabolite of BZ, could contribute to BZ-dependent leukemogenesis by perturbing the functions of SETD2, a histone lysine methyltransferase of hematopoietic relevance. SIGNIFICANCE STATEMENT: Benzoquinone is a major leukemogenic metabolite of benzene. Dysregulation of histone methyltransferase is involved in hematopoietic malignancies. This study found that benzoquinone irreversibly impairs SET domain containing 2, a histone H3K36 methyltransferase that plays a key role in hematopoiesis. Benzoquinone forms covalent adducts on Zn-finger cysteines within the catalytic site, leading to loss of activity, protein crosslinks/oligomers, and concomitant decrease of H3K36me3 histone mark. These data provide evidence that a leukemogenic metabolite of benzene can impair a key epigenetic enzyme.
Asunto(s)
Benceno/metabolismo , Benceno/toxicidad , Benzoquinonas/toxicidad , N-Metiltransferasa de Histona-Lisina/metabolismo , Histonas/metabolismo , Benceno/química , Benzoquinonas/química , Línea Celular , Cisteína/química , Cisteína/efectos de los fármacos , N-Metiltransferasa de Histona-Lisina/antagonistas & inhibidores , N-Metiltransferasa de Histona-Lisina/genética , Histonas/química , Humanos , Leucemia/inducido químicamente , Leucemia/genética , Leucemia/metabolismo , Metilación , Cultivo Primario de Células , Dedos de Zinc/efectos de los fármacosRESUMEN
Despite persistence of leukemic stem cells, patients with chronic myeloid leukemia who achieve and maintain deep molecular responses may successfully stop the tyrosine kinase inhibitor imatinib. However, questions remain unanswered regarding the biological basis of molecular relapse after imatinib cessation. In IMMUNOSTIM, we monitored 51 patients from the French Stop IMatinib trial for peripheral blood T cells and natural killer cells. Molecular relapse-free survival at 24 months was 45.1% (95% CI: 31.44%-58.75%). At the time of imatinib discontinuation, non-relapsing patients had significantly higher numbers of natural killer cells of the cytotoxic CD56dim subset than had relapsing patients, while CD56bright natural killer cells, T cells and their subsets did not differ significantly. Furthermore, the CD56dim natural killer-cell count was an independent prognostic factor of molecular-relapse free survival in a multivariate analysis. However, expression of natural killer-cell activating receptors, BCR-ABL1+ leukemia cell line K562-specific degranulation and cytokine-induced interferon-gamma secretion were decreased in non-relapsing and relapsing patients as compared with healthy individuals. After imatinib cessation, the natural killer-cell count increased significantly and stayed higher in non-relapsing patients than in relapsing patients, while receptor expression and functional properties remained unchanged. Altogether, our results suggest that natural killer cells may play a role in controlling leukemia-initiating cells at the origin of relapse after imatinib cessation, provided that these cells are numerous enough to compensate for their functional defects. Further research will decipher mechanisms underlying functional differences between natural killer cells from patients and healthy individuals and evaluate the potential interest of immunostimulatory approaches in tyrosine kinase inhibitor discontinuation strategies. (ClinicalTrial.gov Identifier NCT00478985).
Asunto(s)
Mesilato de Imatinib/uso terapéutico , Células Asesinas Naturales/citología , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Recuento de Células , Supervivencia sin Enfermedad , Humanos , Interferón gamma/análisis , Células Asesinas Naturales/inmunología , Leucemia Mielógena Crónica BCR-ABL Positiva/inmunología , Leucemia Mielógena Crónica BCR-ABL Positiva/mortalidad , Inhibidores de Proteínas Quinasas/uso terapéutico , Receptores de Células Asesinas Naturales/análisis , RecurrenciaRESUMEN
Acute myeloid leukemia (AML) is a heterogeneous group of malignancies that may be sensitive to the NK cell antitumor response. However, NK cells are frequently defective in AML. In this study, we found in an exploratory cohort (n = 46) that NK cell status at diagnosis of AML separated patients in two groups with a different clinical outcome. Patients with a deficient NK cell profile, including reduced expression of some activating NK receptors (e.g., DNAX accessory molecule-1, NKp46, and NKG2D) and decreased IFN-γ production, had a significantly higher risk of relapse (p = 0.03) independently of cytogenetic classification in multivariate analysis. Patients with defective NK cells showed a profound gene expression decrease in AML blasts for cytokine and chemokine signaling (e.g., IL15, IFNGR1, IFNGR2, and CXCR4), Ag processing (e.g., HLA-DRA, HLA-DRB1, and CD74) and adhesion molecule pathways (e.g., PVR and ICAM1). A set of 388 leukemic classifier genes defined in the exploratory cohort was independently validated in a multicentric cohort of 194 AML patients. In total, these data evidenced the interplay between NK cells and AML blasts at diagnosis allowing an immune-based stratification of AML patients independently of clinical classifications.
Asunto(s)
Citotoxicidad Inmunológica/inmunología , Células Asesinas Naturales/inmunología , Leucemia Mieloide Aguda/inmunología , Receptores de Células Asesinas Naturales/metabolismo , Escape del Tumor/inmunología , Adulto , Anciano , Antígenos CD/inmunología , Moléculas de Adhesión Celular/inmunología , Femenino , Cadenas alfa de HLA-DR/inmunología , Cadenas HLA-DRB1/inmunología , Humanos , Interferón gamma/biosíntesis , Interleucina-15/biosíntesis , Leucemia Mieloide Aguda/diagnóstico , Masculino , Persona de Mediana Edad , Receptores CXCR4/biosíntesis , Receptores de Interferón/biosíntesis , Sialiltransferasas/inmunología , Escape del Tumor/genética , Adulto Joven , Receptor de Interferón gammaRESUMEN
Acute myeloid leukemia (AML) cells are killed by allogeneic NK cells. However, autologous NK cells from AML patients express decreased levels of activating receptors, and show reduced cytotoxicity. Here, we investigated how interactions between NK and AML cells might cause loss of NK-cell activity in patients. Our results show that AML cell lines and primary blasts alter the NK-cell phenotype, reducing their cytotoxic potential upon prolonged contact. Downregulation of NK-cell-activating receptors was contact-dependent and correlated with conjugate formation. Time-lapse imaging of HL60 AML cell line and NK-cell interactions showed a high proportion of noncytolytic contacts. Studies of NK-cell immunological synapses revealed a defect in lytic synapse formation. Namely, despite correct F-actin and LFA-1 recruitment, polarization of lytic granules toward primary blasts or AML cell lines was reduced. The NK-AML cell line synapses showed impairment of CD3ζ recruitment. Attempts to correct these synapse defects by cytokine stimulation of NK cells improved conjugate formation, but not granule polarization. Pretreatment of AML cell lines with the immunomodulating molecule lenalidomide significantly enhanced granule polarization. We speculate that combining immunomodulatory drugs and cytokines could increase AML cell sensitivity to autologous NK cells and reinforce the activity of allogeneic NK cells in adoptive immunotherapy.
Asunto(s)
Citotoxicidad Inmunológica/inmunología , Sinapsis Inmunológicas/inmunología , Células Asesinas Naturales/inmunología , Leucemia Mieloide Aguda/inmunología , Línea Celular Tumoral , Citometría de Flujo , Humanos , Microscopía Fluorescente , Imagen de Lapso de TiempoRESUMEN
Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin's lymphoma in adults. It is generally treated by a combination of chemotherapy and CD20-specific mAbs, such as rituximab, which act, at least partially, by activating antibody-dependent cell-mediated cytotoxicity (ADCC). ADCC involves NK cells, particularly the CD56(dim) NK-cell subset expressing CD16, the low affinity Fcγ receptor. Here, we show that CD16 expression levels are decreased in a cohort of 36 newly diagnosed DLBCL patients compared with those in 20 healthy controls (HCs). CD137, a co-stimulatory molecule expressed on activated NK cells, was also expressed at lower levels in patients compared with controls. Cells sampled from our cohort also showed severely reduced degranulation activity when challenged with rituximab-coated tumor cells, which could not be corrected by stimulation with high doses of IL-2. These results suggest that rituximab-induced NK-cell ADCC could be defective in some DLBCL patients at diagnosis. These patients should be closely monitored and attempts made to improve their NK-cell function.
Asunto(s)
Anticuerpos Monoclonales de Origen Murino/farmacología , Antineoplásicos/farmacología , Citotoxicidad Inmunológica/efectos de los fármacos , Células Asesinas Naturales/efectos de los fármacos , Linfoma de Células B Grandes Difuso/patología , Adulto , Estudios de Casos y Controles , Degranulación de la Célula/efectos de los fármacos , Degranulación de la Célula/inmunología , Células Cultivadas , Proteínas Ligadas a GPI/genética , Proteínas Ligadas a GPI/inmunología , Expresión Génica , Humanos , Inmunidad Celular/efectos de los fármacos , Inmunofenotipificación , Interleucina-2/farmacología , Células Asesinas Naturales/inmunología , Células Asesinas Naturales/patología , Linfoma de Células B Grandes Difuso/diagnóstico , Linfoma de Células B Grandes Difuso/inmunología , Receptores de IgG/genética , Receptores de IgG/inmunología , Rituximab , Miembro 9 de la Superfamilia de Receptores de Factores de Necrosis Tumoral/genética , Miembro 9 de la Superfamilia de Receptores de Factores de Necrosis Tumoral/inmunologíaRESUMEN
Natural killer cells are the first lymphocyte subset to reconstitute, and play a major role in early immunity after allogeneic hematopoietic stem cell transplantation. Cells expressing the activating receptor NKG2C seem crucial in the resolution of cytomegalovirus episodes, even in the absence of T cells. We prospectively investigated natural killer-cell reconstitution in a cohort of 439 adult recipients who underwent non-T-cell-depleted allogeneic hematopoietic stem cell transplantation between 2005 and 2012. Freshly collected blood samples were analyzed 3, 6, 12 and 24 months after transplantation. Data were studied with respect to conditioning regimen, source of stem cells, underlying disease, occurrence of graft-versus-host disease, and profiles of cytomegalovirus reactivation. In multivariate analysis we found that the absolute numbers of CD56(bright) natural killer cells at month 3 were significantly higher after myeloablative conditioning than after reduced intensity conditioning. Acute graft-versus-host disease impaired reconstitution of total and CD56(dim) natural killer cells at month 3. In contrast, high natural killer cell count at month 3 was associated with a lower incidence of chronic graft-versus-host disease, independently of a previous episode of acute graft-versus-host disease and stem cell source. NKG2C(+)CD56(dim) and total natural killer cell counts at month 3 were lower in patients with reactivation of cytomegalovirus between month 0 and month 3, but expanded greatly afterwards. These cells were also less numerous in patients who experienced later cytomegalovirus reactivation between month 3 and month 6. Our results advocate a direct role of NKG2C-expressing natural killer cells in the early control of cytomegalovirus reactivation after allogeneic hematopoietic stem cell transplantation.
Asunto(s)
Infecciones por Citomegalovirus/inmunología , Citomegalovirus/inmunología , Enfermedad Injerto contra Huésped/prevención & control , Neoplasias Hematológicas/complicaciones , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Células Asesinas Naturales/inmunología , Adolescente , Adulto , Enfermedad Crónica , Infecciones por Citomegalovirus/patología , Infecciones por Citomegalovirus/virología , Femenino , Citometría de Flujo , Estudios de Seguimiento , Enfermedad Injerto contra Huésped/etiología , Neoplasias Hematológicas/mortalidad , Neoplasias Hematológicas/terapia , Humanos , Subgrupos Linfocitarios/inmunología , Masculino , Estadificación de Neoplasias , Pronóstico , Estudios Prospectivos , Tasa de Supervivencia , Acondicionamiento Pretrasplante , Trasplante Homólogo , Activación Viral/inmunología , Adulto JovenRESUMEN
Advancements in comprehending myelodysplastic neoplasms (MDS) have unfolded significantly in recent years, elucidating a myriad of cellular and molecular underpinnings integral to disease progression. While molecular inclusions into prognostic models have substantively advanced risk stratification, recent revelations have emphasized the pivotal role of immune dysregulation within the bone marrow milieu during MDS evolution. Nonetheless, immunotherapy for MDS has not experienced breakthroughs seen in other malignancies, partly attributable to the absence of an immune classification that could stratify patients toward optimally targeted immunotherapeutic approaches. A pivotal obstacle to establishing "immune classes" among MDS patients is the absence of validated accepted immune panels suitable for routine application in clinical laboratories. In response, we formed International Integrative Innovative Immunology for MDS (i4MDS), a consortium of multidisciplinary experts, and created the following recommendations for standardized methodologies to monitor immune responses in MDS. A central goal of i4MDS is the development of an immune score that could be incorporated into current clinical risk stratification models. This position paper first consolidates current knowledge on MDS immunology. Subsequently, in collaboration with clinical and laboratory specialists, we introduce flow cytometry panels and cytokine assays, meticulously devised for clinical laboratories, aiming to monitor the immune status of MDS patients, evaluating both immune fitness and identifying potential immune "risk factors." By amalgamating this immunological characterization data and molecular data, we aim to enhance patient stratification, identify predictive markers for treatment responsiveness, and accelerate the development of systems immunology tools and innovative immunotherapies.
RESUMEN
The rules governing natural killer (NK)-cell education in the allogeneic environment created by unrelated hematopoietic stem-cell transplantation (HSCT) are still largely elusive, especially in an unrelated donor setting. NK-cell inhibitory receptors for self-human leukocyte antigen (HLA) play a central role in the acquisition or maintenance of NK-cell functional competence. Therefore, the responsiveness of different NK-cell subsets was assessed as a function of their expression or absence of expression of self-HLA-specific inhibitory receptors, in a large cohort (n = 60) of unrelated HSCT recipients. A fully effective NK-cell education process was achieved within the first year after allogeneic HSCT and lasted for at least 3 years thereafter. In addition, HLA-mismatched HSCT led to a stable education pattern that was determined by the donor's HLA ligands. These data suggest that the NK cell's education partner could be of hematopoietic rather than extrahematopoietic origin. This donor-ligand-driven NK-cell education model would suggest a sustained graft-versus-leukemia effect after HLA-mismatched HSCT.
Asunto(s)
Donantes de Sangre , Antígenos HLA/genética , Trasplante de Células Madre Hematopoyéticas/métodos , Células Asesinas Naturales/metabolismo , Adolescente , Adulto , Anciano , Niño , Preescolar , Femenino , Genotipo , Histocompatibilidad/genética , Humanos , Células K562 , Células Asesinas Naturales/inmunología , Cinética , Ligandos , Masculino , Persona de Mediana Edad , Subfamília C de Receptores Similares a Lectina de Células NK/inmunología , Subfamília C de Receptores Similares a Lectina de Células NK/metabolismo , Receptores KIR2DL3/inmunología , Receptores KIR2DL3/metabolismo , Receptores de Células Asesinas Naturales/inmunología , Receptores de Células Asesinas Naturales/metabolismo , Trasplante Homólogo , Adulto JovenRESUMEN
Natural Killer (NK) cells participate in the defense against infection by killing pathogens and infected cells and secreting immuno-modulatory cytokines. Defects in NK cell activity have been reported in obese, diabetic, and elderly patients that are at high risk of developing infected chronic wounds. Calcium alginate dressings are indicated for the debridement during the inflammatory phase of healing. Since calcium ions are major activators of NK cells, we hypothesized that these dressings could enhance NK functions, as investigated in vitro herein. Primary human blood NK cells were freshly-isolated from healthy volunteers and exposed to conditioned media (CM) from two alginate dressings, Algosteril® (ALG, pure Ca2+ alginate) and Biatain® Alginate (BIA, Ca2+ alginate with CMC), in comparison with an exogenous 3mM calcium solution. Our results demonstrated that exogenous calcium and ALG-CM, but not BIA-CM, induced NK cell activation and enhanced their capacity to kill their targets as a result of increased degranulation. NK cell stimulation by ALG depended on the influx of extracellular Ca2+ via the SOCE Ca2+ permeable plasma membrane channels. ALG-CM also activated NK cell cytokine production of IFN-γ and TNF-α through a partly Ca2+-independent mechanism. This work highlights the non-equivalence between alginate dressings for NK cell stimulation and shows that the pure calcium alginate dressing Algosteril® enhances NK cell cytotoxic and immuno-modulatory activities. Altogether, these results underline a specific property of this medical device in innate defense that is key for the cutaneous wound healing process.
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Alginatos , Calcio , Humanos , Anciano , Alginatos/farmacología , Cicatrización de Heridas , Vendajes , Células Asesinas NaturalesRESUMEN
Myelodysplastic syndromes (MDS) are clonal hematopoietic disorders, representing high risk of progression to acute myeloid leukaemia, and frequently associated to somatic mutations, notably in the epigenetic regulator TET2. Natural Killer (NK) cells play a role in the anti-leukemic immune response via their cytolytic activity. Here we show that patients with MDS clones harbouring mutations in the TET2 gene are characterised by phenotypic defects in their circulating NK cells. Remarkably, NK cells and MDS clones from the same patient share the TET2 genotype, and the NK cells are characterised by increased methylation of genomic DNA and reduced expression of Killer Immunoglobulin-like receptors (KIR), perforin, and TNF-α. In vitro inhibition of TET2 in NK cells of healthy donors reduces their cytotoxicity, supporting its critical role in NK cell function. Conversely, NK cells from patients treated with azacytidine (#NCT02985190; https://clinicaltrials.gov/ ) show increased KIR and cytolytic protein expression, and IFN-γ production. Altogether, our findings show that, in addition to their oncogenic consequences in the myeloid cell subsets, TET2 mutations contribute to repressing NK-cell function in MDS patients.
Asunto(s)
Dioxigenasas , Síndromes Mielodisplásicos , Humanos , Metilación , Síndromes Mielodisplásicos/metabolismo , Células Asesinas Naturales , Azacitidina/farmacología , Receptores KIR/genética , Mutación , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Dioxigenasas/metabolismoRESUMEN
WHIM Syndrome is a rare immunodeficiency caused by gain-of-function CXCR4 mutations. Here we report a decrease in bone mineral density in 25% of WHIM patients and bone defects leading to osteoporosis in a WHIM mouse model. Imbalanced bone tissue is observed in mutant mice combining reduced osteoprogenitor cells and increased osteoclast numbers. Mechanistically, impaired CXCR4 desensitization disrupts cell cycle progression and osteogenic commitment of skeletal stromal/stem cells, while increasing their pro-osteoclastogenic capacities. Impaired osteogenic differentiation is evidenced in primary bone marrow stromal cells from WHIM patients. In mice, chronic treatment with the CXCR4 antagonist AMD3100 normalizes in vitro osteogenic fate of mutant skeletal stromal/stem cells and reverses in vivo the loss of skeletal cells, demonstrating that proper CXCR4 desensitization is required for the osteogenic specification of skeletal stromal/stem cells. Our study provides mechanistic insights into how CXCR4 signaling regulates the osteogenic fate of skeletal cells and the balance between bone formation and resorption.
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Síndromes de Inmunodeficiencia , Osteoporosis , Enfermedades de Inmunodeficiencia Primaria , Receptores CXCR4 , Animales , Ratones , Síndromes de Inmunodeficiencia/genética , Mutación , Osteogénesis/genética , Osteoporosis/genética , Enfermedades de Inmunodeficiencia Primaria/genética , Receptores CXCR4/genética , Receptores CXCR4/metabolismo , HumanosRESUMEN
BACKGROUND: Systemic inflammatory and autoimmune diseases (SIADs) occur in 10-20% of patients with myelodysplastic syndrome (MDS). Recently identified VEXAS (Vacuoles, E1 enzyme, X-linked, Autoinflammatory, Somatic) syndrome, associated with somatic mutations in UBA1 (Ubiquitin-like modifier-activating enzyme 1), encompasses a range of severe inflammatory conditions along with hematological abnormalities, including MDS. The pathophysiological mechanisms underlying the association between MDS and SIADs remain largely unknown, especially the roles of different myeloid immune cell subsets. The aim of this study was to quantitatively evaluate peripheral blood myeloid immune cells (dendritic cells (DC) and monocytes) by flow cytometry in MDS patients with associated SIAD (n = 14, most often including relapsing polychondritis or neutrophilic dermatoses) and to compare their distribution in MDS patients without SIAD (n = 23) and healthy controls (n = 7). Most MDS and MDS/SIAD patients had low-risk MDS. Eight of 14 (57%) MDS/SIAD patients carried UBA1 somatic mutations, defining VEXAS syndrome.Compared with MDS patients, most DC and monocyte subsets were significantly decreased in MDS/SIAD patients, especially in MDS patients with VEXAS syndrome. Our study provides the first overview of the peripheral blood immune myeloid cell distribution in MDS patients with associated SIADs and raises several hypotheses: possible redistribution to inflammation sites, increased apoptosis, or impaired development in the bone marrow.
Asunto(s)
Monocitos , Síndromes Mielodisplásicos , Humanos , Síndromes Mielodisplásicos/genética , Inflamación , Células Dendríticas , MutaciónRESUMEN
BACKGROUND & AIMS: The natural killer group 2 member D (NKG2D) is a stimulatory receptor expressed on a subset of mucosal and peripheral CD4+ T cells in patients with Crohn's disease (CD) and other inflammatory diseases. Ligand activation of NKG2D in patients induces CD4+ T cells to release T-helper (Th) 1 cytokines and become cytotoxic. We investigated the Th17 cytokines produced by T cells that express NKG2D in blood and intestinal mucosa samples from patients with CD. METHODS: We isolated CD4+ T cells from peripheral blood and lamina propria samples of patients with CD or ulcerative colitis (UC) and healthy individuals (controls). We analyzed the phenotype and functions of the CD4+NKG2D+ T cells and the cytokines they produce in response to NKG2D stimulation. RESULTS: In patients with CD, CD4+ T cells that express NKG2D produced high levels of interleukin (IL)-17 and IL-22 and expressed high levels of CCR6, the IL-23 receptor, CD161, and RORC (a transcription factor that regulates expression of Th17 cytokines). CD4+ T cells that produced IL-17 expressed high levels of NKG2D and CD161. Costimulation of NKG2D and the T-cell receptor (TCR) significantly increased production of IL-17 and tumor necrosis factor α by CD4+ T cells, compared with activation of only the TCR. CD4+NKG2D+ T cells also responded to Th17 polarization. CONCLUSIONS: NKG2D is a functional marker of CD4+ T cells that produce IL-17 in patients with CD, via costimulation of the TCR and NKG2D. Reagents developed to block NKG2D might reduce gastrointestinal inflammation in patients with CD.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Colitis Ulcerosa/inmunología , Enfermedad de Crohn/inmunología , Citocinas/metabolismo , Mediadores de Inflamación/metabolismo , Mucosa Intestinal/inmunología , Subfamilia K de Receptores Similares a Lectina de Células NK/agonistas , Células Th17/inmunología , Adolescente , Adulto , Animales , Estudios de Casos y Controles , Línea Celular Tumoral , Colitis Ulcerosa/sangre , Colitis Ulcerosa/genética , Enfermedad de Crohn/sangre , Enfermedad de Crohn/genética , Citocinas/genética , Femenino , Citometría de Flujo , Francia , Humanos , Inmunofenotipificación/métodos , Ligandos , Masculino , Ratones , Persona de Mediana Edad , Subfamilia B de Receptores Similares a Lectina de Células NK/inmunología , Fenotipo , Receptores de Antígenos de Linfocitos T/agonistas , Adulto JovenRESUMEN
Changes in the cell envelope composition of mycobacteria cause major changes in cytokine profiles of infected antigen presenting cells. We describe here the modulation of inflammatory responses by Mycobacterium abscessus, an emerging pathogen in cystic fibrosis. M. abscessus is able to switch from a smooth (S) to a rough (R) morphotype by the loss of a surface glycopeptidolipid. R variants are associated with severe clinical forms and a 'hyper-proinflammatory' response in ex vivo and in vivo models. Using partitioning of cell surface components we found that a complex fraction, more abundant in R variants than in S variants, made a major contribution to the TLR-2-dependent hyper-proinflammatory response induced by R variants. Lipoproteins were the main TLR-2 agonists in this fraction, consistent with the larger amounts of 16 lipoproteins in cell surface extracts from R variants; 15 out of 16 being more strongly induced in R variant than in S variant. Genetic interruption of glycopeptidolipid pathway in wild-type S variant resulted in R phenotype with similar induction of lipoprotein genes. In conclusion, R morphotype in M. abscessus is associated with increased synthesis/exposure at the cell surface of lipoproteins, these changes profoundly modifying the innate immune response through TLR-2-dependent mechanisms.
Asunto(s)
Lipoproteínas/metabolismo , Mycobacterium/metabolismo , Transducción de Señal , Receptor Toll-Like 2/metabolismo , Animales , Membrana Celular/inmunología , Citocinas/biosíntesis , Citocinas/inmunología , Citocinas/metabolismo , Electroforesis en Gel de Poliacrilamida , Técnica del Anticuerpo Fluorescente , Glicopéptidos/inmunología , Glicopéptidos/metabolismo , Células HEK293 , Humanos , Inflamación/inmunología , Lipoproteínas/inmunología , Macrófagos , Ratones , Mycobacterium/inmunología , Mycobacterium/patogenicidad , Infecciones por Mycobacterium/inmunología , Infecciones por Mycobacterium/microbiología , Fenotipo , Reacción en Cadena de la Polimerasa , Receptor Toll-Like 2/agonistas , VirulenciaRESUMEN
Innate lymphoid cells (ILCs) - which include cytotoxic Natural Killer (NK) cells and helper-type ILC - are important regulators of tissue immune homeostasis, with possible roles in tumor surveillance. We analyzed ILC and their functionality in human lymph nodes (LN). In LN, NK cells and ILC3 were the prominent subpopulations. Among the ILC3s, we identified a CD56+/ILC3 subset with a phenotype close to ILC3 but also expressing cytotoxicity genes shared with NK. In tumor-draining LNs (TD-LNs) and tumor samples from breast cancer (BC) patients, NK cells were prominent, and proportions of ILC3 subsets were low. In tumors and TD-LN, NK cells display reduced levels of NCR (Natural cytotoxicity receptors), despite high transcript levels and included a small subset CD127- CD56- NK cells with reduced function. Activated by cytokines CD56+/ILC3 cells from donor and patients LN acquired cytotoxic capacity and produced IFNg. In TD-LN, all cytokine activated ILC populations produced TNFα in response to BC cell line. Analyses of cytotoxic and helper ILC indicate a switch toward NK cells in TD-LN. The local tumor microenvironment inhibited NK cell functions through downregulation of NCR, but cytokine stimulation restored their functionality.
Asunto(s)
Antineoplásicos , Neoplasias de la Mama , Neoplasias de la Mama/metabolismo , Femenino , Humanos , Inmunidad Innata , Células Asesinas Naturales/metabolismo , Ganglios Linfáticos/patología , Microambiente TumoralRESUMEN
The MHC class I-related chain A (MICA) molecules exist as membrane-bound and soluble isoforms and are encoded by a polymorphic gene. Their genetic and phenotype characteristics have been studied in various pathologic settings but not in the context of hematopoietic stem cell transplantation (HSCT). Here, we evaluated whether MICA-related features namely MICA-129 gene polymorphism, serum levels of soluble MICA (sMICA) and anti-MICA antibodies (MICA Abs) before and after HSCT could influence the incidence of chronic graft-versus-host disease (cGVHD) and relapse of their disease in 211 HLA-identical sibling pairs and in a subset of 116 recipients, respectively. Although the MICA-129 val/val genotype and elevated sMICA serum levels after HSCT are independently associated with the incidence of cGVHD (P = .002 and .001) regardless of history of acute GVHD, the presence of MICA Abs before transplantation confers protection against cGVHD (P = .04). There is an inverse relationship between MICA Abs and sMICA, suggesting an antibody-based neutralization of deleterious effects of sMICA. Similarly, these genetic and phenotype characteristics of MICA influence the incidence of relapse. Altogether, these data suggest that the studied MICA genotype and phenotype specificities could be used as relevant biomarkers for cGVHD monitoring.